The numbers on the back of the bottle tell you more than anything on the front. Here is how to read them in a few minutes.

A sports drink can be a useful piece of training kit, or it can be a soft drink with better marketing. The difference is not on the front of the bottle. It sits in the nutrition information panel, and reading it takes about five minutes once you know what to look for.

What you need

The bottle, its nutrition information panel and the ingredients list. Packaged foods sold in Australia must carry labels showing safety and nutrition information, so everything you need is already on the pack. No apps or spreadsheets required.

Step 1: Find the serving size and check it against the bottle

Start at the top of the panel. It shows the size of a standard serving and the number of servings per package. The common trap is a panel written per 250 ml serving in a 600 ml bottle, which quietly makes every number look smaller than what you will actually drink. Multiply the per-serve figures by the number of serves in the bottle, or read the per 100 ml column when comparing products. This one check does more than any claim on the front label.

Step 2: Look at the carbohydrate number and what it’s for

Carbohydrate is the fuel side of the equation. The Food Standards Code currently sets a minimum carbohydrate content for electrolyte drinks of 50 grams per litre. Food Standards Australia New Zealand has proposed lowering that minimum to 20 g/L after finding that drinks with a carbohydrate content of 2% had a similar effect on rehydration and exercise performance as drinks meeting the current rule, though that change is still a proposal rather than the law of the moment.

Why should a shopper care? The carbohydrate number tells you whether the drink is built to fuel long, hard sessions or mainly to replace fluid with a little taste. It also drives the kilojoule count, because carbohydrate is energy, so a higher number means more kilojoules per serve. If your sessions are short and easy, those kilojoules may be ones you did not need.

Step 3: Check the sodium and other electrolytes

Sodium is the headline electrolyte. Fluids containing sodium are recommended during long-duration or high-intensity exercise to help limit fluid loss, and sodium also helps the body retain fluid during recovery. On the panel, compare sodium in milligrams per 100 ml across products, because the range between drinks is wide. Some also list potassium, magnesium and calcium, and a few add B vitamins. Knowing that is fine; buying on the strength of it is not.

Step 4: Spot the added sugar and compare with soft drink

Sugar is a type of carbohydrate, and the panel shows total sugars per serve and per 100 ml. The ingredients list runs in order of weight, so if a sugar such as glucose or sucrose sits near the top, sugar is a large share of what you are drinking. For context, one label comparison found about 39 grams of sugar in a 12-ounce (about 355 ml) cola versus about 21 grams in a popular sports drink. Less than soft drink, still meaningful.

The World Health Organization suggests keeping sugar to 10% or less of daily energy intake, about 50 grams a day for an adult, with more health benefits below 5%, about 25 grams. Frequent sugary drinks also expose teeth to the acid that mouth bacteria produce, which wears away enamel over time.

Step 5: Match the drink to the session you actually do

Now connect the numbers to your week.

What you are doing	What the label tells you
Short or easy sessions, mostly under an hour	Carbohydrate and sodium matter little; water will do the job
High-intensity or long sessions of an hour or more	Carbohydrate and sodium become genuinely useful, since this is the exercise the drinks are formulated for
Two sessions in a day or exercise in the heat	Sodium helps you rehydrate and hold onto fluid before the next session

The honest pattern in the research is that the benefits turn up with demanding exercise, not everyday activity.

Step 6: Consider whether plain water does the job

Water is calorie-free, free or close to it, and the drink of choice with and between meals. For a non-athlete, a sports drink is simply another sugary drink, and sipping one without matching exercise adds kilojoules without much else. Flavour does serve a purpose, though: a lightly flavoured drink can encourage you to drink more and more often, which helps when fluid loss is the real concern. If that is what gets you through a long summer session, steps 2 to 4 tell you how much carbohydrate and sodium comes along with it.

Step 7: Know the claims that need a second look

The front of the bottle is where a second read earns its keep. Food Standards Australia New Zealand has proposed permitting only three specific health claims on electrolyte drinks and prohibiting all others, including self-substantiated ones, so shoppers get clearer guidance. Separate fair trading laws already prohibit false, misleading or deceptive representations about food. Terms describing how concentrated a drink is matter because concentration affects how quickly the stomach empties, and a shorter ingredient list generally leaves more room for the ingredients doing the work, namely carbohydrate and sodium. If a claim is vague, price the bottle on its panel instead. For advice on your own needs, your GP or an accredited sports dietitian is the right starting point.

Whatever the label says, the drink is one small part of the picture. Our glossary of sports nutrition terms decodes the jargon you will meet on panels and in training advice, and if you are building up to your first longer sessions, the eight-week walk-to-jog plan shows the kind of gradual progression where these choices start to matter.

Questions we get

Are sports drinks better than water?

For high-intensity or long sessions of an hour or more, the carbohydrate and sodium in a sports drink can be genuinely useful. For short or easy sessions and everyday activity, water is calorie-free and does the job.

How much carbohydrate should a sports drink contain?

The Food Standards Code sets a minimum of 50 grams per litre for electrolyte drinks. Food Standards Australia New Zealand has proposed lowering that to 20 g/L after finding that drinks with 2% carbohydrate had a similar effect on rehydration and exercise performance.

Can children drink sports drinks?

For children and adolescents exercising vigorously for more than 60 minutes, sports drinks may help prevent dehydration when coaches or parents are monitoring. For routine or play-based activity, these drinks are usually unnecessary.

How do I compare two drinks fairly?

Use the per 100 ml column rather than the per-serve column, because serving sizes differ between products. Sugar per 100 ml is an easy way to compare products side by side.

This article is general information, not personalised medical or fitness advice. Talk to your GP, a physiotherapist or an accredited exercise physiologist before starting a new exercise program if you have a health condition or injury, are pregnant or haven’t been active for a while. In an emergency, call 000.